Senior Citizens With Conviction

By Christopher Shea

A gray-haired jury ought to worry a defendant, according to a study of felony trials in two Florida counties, from 2000 to 2010: Older jurors lead to higher rates of conviction. Defense attorneys seem to grasp this, as they use their peremptory strikes disproportionately to exclude older jurors from the jury, the study found. And so do prosecutors, who tend to strike young people.

Because so many non-random factors affect the selection of jurors, the researchers trained their attention not on the seated jury but on the jury pool, whose average age fluctuates randomly, day to day. (There’s an implicit connection, if not a direct one, between the age of the pool and the seated jury.) The link between age and conviction rates in the more than 700 trials studied was “straightforward and striking”: When the average age of the jury pool was greater than 50, which was the case about half the time, the conviction rate was 79%. When the average age of the pool was below 50, the conviction rate dropped to 68%.

The researchers had details on peremptory strikes for one of the two counties studied. The average age of a juror struck by prosecutors was 47.1, and by defense lawyers 51.6

The effect was driven by the treatment of male defendants: Female defendants, who made up fewer than 10% of the total, were actually convicted less often when the jury pool was older. “You might have a mental impression of older jurors, looking at mostly younger male defendants, and thinking ‘The youth have run amok,’” says Duke’s Patrick Bayer, a co-authors of the study. “They might have different ideas about the likelihood of women being involved in crime.”

Florida uses juries of six people, with two alternates, rather than the traditional twelve — a size that has become popular, nationally, as a cost-cutting measure. The authors point out that small juries heighten the age effect, because they cause the average age of juries to vary more, from trial to trial. Without explicitly taking age into account, therefore, expanding the size of juries would reduce age-related unfairness.